Coherent optical receivers process traffic, in the form of optical signals, received from an optical network. Coherent optical receivers process the optical signals by performing operations on the optical signals, such as polarization beam splitting, demodulation, analog-to-digital conversion, etc. The processing, performed by the coherent optical receivers, usually includes coherent processing using a local oscillator that is matched to a carrier frequency that is generated by a remote oscillator in an optical transmitter.
Differential coherent detection techniques, employed in optical receivers, may minimize cycle slip-induced bit errors associated with traffic that has been phase modulated (e.g., based on binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), etc.). Reducing the errors caused by the cycle slips may result in reducing a bit error rate associated with traffic. Unfortunately, the differential coherent detection techniques often introduce a noise penalty, which may reduce system range.